public void fireStateChanged() {
   changeSupport.fireStateChanged();
 }
 public void removeChangeListener(ChangeListener l) {
   changeSupport.removeChangeListener(l);
 }
 public ChangeListener[] getChangeListeners() {
   return changeSupport.getChangeListeners();
 }
 public void addChangeListener(ChangeListener l) {
   changeSupport.addChangeListener(l);
 }